Dimitrov, Nikolay, Ivan Georgiev, and Petar Danchev. “Refraction Correction in Precise Leveling Observations for National Leveling Network First Order”. Geodesy and Cartography 46, no. 4 (December 16, 2020): 159-162. Accessed November 22, 2024. https://btp.vgtu.lt/index.php/GAC/article/view/11555.